Jump to content
Ultimate Subaru Message Board

No spark from coil, 86 brat


Recommended Posts

This has been my dianosis so far. .. car stopped stopped running but turned over, pulled a plug and held it with plyers againts the block and no spark, pulled the coil wire from distributor and no spark. Put the 12v test light to positive side of the coil and there was light with igntion on, hooked it onto the negative side while turning the engine and it pulsed with the sound of the turning engine, pulled the fuel line from where it meets the carb, drained excess gas into a jar, placed the line into a baby jar resting on the block and turned the engine over a few times while giving it a little gas, jar was half full... I had already replaced the plugs and wires (ngk) a few weeks ago... so then I replaced the coil, and replaced the linkable fuses but still nothing...

Link to comment
Share on other sites

The module in the dizy would effect the spark from the coil?

 

 

Yes.

 

I went through this too.  I believe the ignition module sends a signal to the coil when it senses engine rotation, telling the coil to fire.

 

 

Generally they start to show failure randomly at operating temps, causing misfires or stalling.  Eventually they fail all together.  

Though sometimes they just fail.  The last one I had fail did just that, with no warning at all.

Link to comment
Share on other sites

Thanks for the info Ivans Imports. If that is the case then I have to assume the module is working since the negative side of the coil showed signs of going to ground using the test light, which should make the coil fire. So I have wonder if the coil wire is bad.

Link to comment
Share on other sites

The first thing I did was replace thr coil wire. .. Though the second time I did the - side coil test it didnt have a stong pulse it just pretty much turned the light to really dim/ almost off... My question now is what should the pulse look like?

Link to comment
Share on other sites

Similar dead-in-the-water dizzy issues..

 

My testing has gotten to the point where I have a ground from the ICM B/W lug on the distributor (hitachi)

with nothing else hooked up.compared that to the 'good' reference. no ground. So I'm getting another module. Allegedly the friend who checked noted a spark, but I didn't see it myself.

Link to comment
Share on other sites

So I went and looked at mossgreens brat,

sure I could sort it out having had this issue before.

 

We installed a new (JY) ignition module,

New coil, replaced all fusible links,

verified grounds (coil bracket, etc.)

 

Still no spark.

 

What's a simple method of assuring the module is no good, as I'm finding it hard to believe we can't get a spark.

 

Thanks,

Pete

Link to comment
Share on other sites

If it has a ECM that could do it. On a 83 turbo wagon i had it suddenly wouldn't run one day and it had no spark along with fuel pump not working right, so I replaced the coil plus cleaning conections thinking that was it. Turns out it was't so I put in a spair ECM before I looked for a distributor because they're hard to find for turbos from the module having 4 wires instead of 2. The ECM was the problem in my case for sure since spark retured and it fired right up after replacing it along with normal fuel pulsing.

Link to comment
Share on other sites

You make another good point Ivans Imports. If the OP hasn't verified the disty is turning while cranking the engine that needs to be done next. If that is okay then going from what was stated in post 11 it indicates that either the wiring from the disty or, the control unit shown in the above parts view is bad. I think it is the only thing left in the circuit that hasn't been replaced.

Link to comment
Share on other sites

No ECU in this car, it's running a Weber 32/36,

although good point if it was FI

 

The distributor shaft indeed turns while cranking.

The coil leads could be potentially hooked up wrong,

as its easy enough to fudge.

 

BW from body = 12v IG. = POS


BW from Disty = POS

 

Noise Condenser= POS

 

Yellow from disty = NEG


Yellow from body = Tach signal wire = NEG

 

Correct?

Link to comment
Share on other sites

No ECU in this car, it's running a Weber 32/36,

although good point if it was FI

 

The distributor shaft indeed turns while cranking.

The coil leads could be potentially hooked up wrong,

as its easy enough to fudge.

 

BW from body = 12v IG. = POS

BW from Disty = POS

 

Noise Condenser= POS

 

Yellow from disty = NEG

Yellow from body = Tach signal wire = NEG

 

Correct?

That's my impression. (same problem, almost. That' s why I've been posting here.. )

 

except my BW from disty is reading continuity to ground unhooked up to the coil.

 

 

Next time you're metering, check that. I'm just curious. There was a relevant to the discussion diagram but it seems to have gone away.

Link to comment
Share on other sites

Placing a test light probe on the minus side of the coil should make the light flash brightly while cranking the engine if things are good. If the light stays on steady or there is no light then either the module inside the disty is bad or voltage isn't getting past the positive side of the coil.

Link to comment
Share on other sites

Placing a test light probe on the minus side of the coil should make the light flash brightly while cranking the engine if things are good. If the light stays on steady or there is no light then either the module inside the disty is bad or voltage isn't getting past the positive side of the coil.

 

Or the wiring between the coil and disty is bad.....

Or the magnet in the disty has problems(even cracked ones seem to work though)

 

Quick and dirty way to test the other components is to intermittently ground coil negative(like the module is supposed to) and see if you have spark.(Key on.)

Link to comment
Share on other sites

 

 

What's a simple method of assuring the module is no good, as I'm finding it hard to believe we can't get a spark.

 

Thanks,

Pete

 

Use the diode test function of a multimeter to compare it to a known good one.

Test between all 3 connections,both polarities on each.

Any significant difference confirms the bad one.

 

Lacking one for comparision,shorts or opens are signs of trouble.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...